A systematic review of microplastics occurrence, characteristics, identification techniques and removal methods in ASEAN and its future prospects

This systematic review aims to comprehensively review and critically analyze the status of microplastics (MPs) in ASEAN countries. 273 publications related to ASEAN were shortlisted for analysis. The findings showed that 28 (10.2%) articles are review-based studies, and 245 articles (89.8%) are data analysis or experiment-based studies published between 2017 and December 31, 2022. Among the 10 ASEAN countries, Indonesia and Malaysia reported the highest number of studies in the year 2021, while Laos has not published any articles on MPs and Myanmar has the least (only one). Most of the samplings of MPs were done in sediments, water sources, and marine ecosystems, followed by studies of solid waste and air. Only 13 articles out of 273 reported on the effects of MPs on human health in Malaysia, Indonesia, Thailand, and Singapore. Microscopy examination and FTIR techniques were commonly used for MP detection. Fiber and fragment shapes and all common colors were identified. Sizes and concentrations of particles were reported randomly without any specific unit of measurement. Removal studies were focused on drinking water. Heterogeneity in sampling methods, analysis techniques, and reporting units hinders comparison and conclusion on the present state of knowledge. Future remedies focus on homogeneity in MPs analysis and characterization. This comprehensive review would be beneficial to policymakers and researchers in ASEAN to develop effective strategies for addressing MPs issues in the future.